Embodiments of the invention relate generally to electronic devices and, more particularly, to a system for providing thermal management of electronic devices in a balanced fashion and via multiple thermal pathways.
Small form electronic devices, such as handheld computing devices (e.g., smart phones, tablet computers e-book readers, etc.) and embedded computing systems, present significant thermal management challenges. There is ongoing user demand for devices that are not only smaller form factor for greater portability but also powerful enough to handle video and other computing intensive tasks. The provision for significant computing power in a relatively small form device often translates into the need for significant thermal management of the heat dissipating devices.
One common solution used to transfer heat from a processor in a small form device includes the use of a heat spreader that is in thermal contact with the processor or active device/component. The heat spreader is in turn, in thermal contact with a heat exchanger via a heat pipe or other structure—with the heat exchanger often including an air mover, such as a fan, that vents air to the external ambient by way of a small vent.
It is recognized, however, that conventional thermal management systems such as the one described above have known limitations and drawbacks associated therewith. As one example, it is recognized that in such conventional thermal management systems only one mechanism is in place to remove the heat—that being the heat pipe and heat exchanger connected to a surface of the processor/active device. Therefore, if the heat pipe or a component of the heat exchanger were to fail (e.g., the fan in the heat exchanger plugging with dust), a potential thermal runaway could occur that causes overheating and/or damage to the device to occur.
As another example, even during normal operation of a conventional thermal management system, it is recognized that a portion of the heat generated by the processor or active component is not transferred to the heat pipe, but travels through a back surface of the processor (i.e., surface not connected to the heat pipe) to the printed circuit board (PCB) on which the processor is mounted. Accordingly, this portion of the heat that goes from the processor to the PCB has a poor thermal management, and this heat can have a thermal impact on neighboring devices, as well as create localized hot spots on the PCB. Given the fact that, in many applications, the PCB is in a close proximity to the case/skin of the computing device, heat transferred to the PCB can therefore also lead to hot spots on the case/skin, with which a user may come in contact with.
Still another potential pitfall associated with the conventional thermal management system just described is the issue of both acoustic and electrical noise associated with a cooling fan. Such issues can be reduced though not completely eliminated through the use of appropriate noise filtering circuitry and fan and vent design. However, there remains the issue of power consumption to run the fan.
Therefore, it would be desirable to provide a thermal management system for small form electronic devices that overcomes the aforementioned drawbacks, with such a system providing multiple thermal pathways, greater reliability, and reduced power consumption and acoustic noise generation.